The present invention relates to an improved storage container. This container is particularly useful for the long-term storage of waste materials which may or may not include moderate levels of radionuclides.
The safe long term storage of chemical and nuclear materials which are environmentally hazardous has become a major problem for the developed nations of the world. There are a relatively minor number of disposal sites which can accommodate these materials. In many cases the waste material must be shipped and stored or buried in an approved container having an assured minimum lifetime. A broad range of government regulations exist which define the requirements that must be met by waste material storage containers for use in various types of service.
One problem frequently encountered with waste storage containers, particularly those made in larger sizes, is in assuring a tight leak-proof fit of a lid or cover which is applied after the container is filled. My earlier patent, U.S. Pat. No. 4,381,844, describes a suitable sealing means for such a container. It shows a relatively large metallic container having a right rectangular configuration. The upper periphery is surrounded by an outwardly extending flange which mates with a similar planar portion on the lid. The lid is secured with four hinge-like fasteners. The hinge pins can be inserted after the container is filled to securely fasten the lid. The gasket used between the lid and the container flange consists of a piece of flexible fabric-like material longitudinally folded upon itself. The folded portion is allowed to extend for a short distance within the container, while the two lips of the gasket are adhesively bonded to the container flange and lid. Other remotely similar gasket types are shown in U.S. Pat. No. 3,230,290 to Nelson and U.S. Pat. No. 3,269,585 to Christensen. U.S. Pat. No. 3,406,863 to Wenzel et al. shows a somewhat different approach to gasketing a high pressure vessel. U.S. Pat. No. 3,481,503 to Kloess et al. shows a more conventionally gasketed freight container.
While all of the above mentioned devices have apparently been useful for the purposes intended, none has been fully satisfactory for the long-term storage of waste materials. As one example of a problem, the outwardly extending flange on the construction, shown in my earlier patent, prevents tight side-to-side storage configurations with the result that a significant amount of valuable space is wasted. Further, the critical fold portion of the gasket is exposed to the contents which may induce premature deterioration. As will be seen, the present invention overcomes these and other problems in the construction of durable high integrity storage containers.